[Page 78]The term neurocognitive disorder (NCD) refers to a group of cognitive impairments that are caused by a variety of diseases including cardiovascular disease (e.g., stroke), degenerative diseases (e.g., Alzheimer’s disease [AD], Lewy body disease), accidents (e.g., head trauma, gunshot wounds), and other processes that affect the brain (e.g., toxicity, HIV/AIDS).

The core features of NCDs are acquired cognitive impairments that represent a decline from previous level of function. NCDs are diagnosed based on documented deficits in six relatively well-defined cognitive domains: (1) attention, (2) executive function, (3) learning and memory, (4) language, (5) perceptual-motor function, and (6) social cognition. Individuals with NCDs demonstrate a decreased cognitive function in one or more of these domains and functional impairment in daily activities that are not better explained ...